Structural studies are in progress, concerned with the polyene antibiotics hamycin, aureofungin, and candimycin, with the peptide antibiotics berninamycin and antiamoebin, and with scopafungin. Biosynthetic studies are concerned with the aminocyclitol antibotic neomycin, with the diazaanthracene antibiotic nybomycin, with the ansamycin antibiotics geldanamycin and streptovaricin, and with chloramphenicol. Synthetic efforts involve neomycin, streptovaricin, geldanamycin, nybomycin, and the acyl tetramic acid antibiotics tirandamycin and streptolydigin.